Equipment

Panoramic x-ray machines are composed of an exposure control panel, a C-arm and a patient positioning device.

Control panel and exposure switch – The control panel contains the on/off switch, program control selector, exposure selectors (milliamperage control, kilovoltage control), x-ray emission signal and may contain the exposure switch.

The complexity of the control panel increases with the incorporation of features such as multiple program options and automatic exposure control (AEC) features.

Figure 20. OP100

Example of full feature exposure control (OP100; Instrumentarium Imaging).

Control panel also acts as the exposure switch.

Figure 21. PC1000

Example of limited feature exposure control (PC1000; Panoramic Corp.) this machine has only two programs and no AEC feature. The exposure “dead man” switch is separate.

Legend:

1=On/off switch
(PC1000 only)

2 = Program Control Selectors

3 = kVp control

4 = kVp display

5 = x-ray emission light

OP100 Only:

6 = Exposure switch

7 = Panoramic exposure modes

8 = mA display

9 = AEC adjustment.

C-arm (x-ray tubehead/receptor assembly) – The relationship of the x-ray tubehead is fixed spatially to the receptor assembly by a fixed C-arm support. The panoramic x-ray tubehead is similar to a dental tubehead; however, unlike the dental tubehead there is both pre- and post patient linear collimation to provide a slit beam. The receptor assembly must accept either a flexible cassette or rigid cassette. A flexible cassette is mounted on a drum. Rigid cassettes can be either curved or flat and are inserted into a similarly shaped receptor assembly.

Figure 22.

Flexible cassette being mounted on drum shaped receptor assembly.

Figure 23.

Rigid cassette being mounted on flat receptor assembly.

Patient Positioning Device – The radiographer must be familiar with the operation of the patient positioning device as it is this apparatus that is used to position the patient’s head into the focal trough of the machine. This device comprises a head holder and a chin rest/bite block. The chin rest/bite block is used to stabilize the patient’s dentition in the anteroposterior direction whereas the head holder is used to stabilize the orientation of the patient’s head in both the vertical and horizontal planes.